The starter is what gives the crank that initial turning force. The starter consists of a direct current electric motor and a solenoid. Using the battery power from a fully charged battery, thanks to your alternator; you hop into your car and turn the key. The starter’s gear is advanced by its pinion shaft and the starter’s gears engage the teeth of the flywheel and turn it. While the battery supplies power to the fuel pump which delivers fuel to the injectors; and the power is delivered to the coil which allow the spark plugs to fire, the engine starts. Once the engine is running the starter’s gear is retracted from the flywheel, then the alternator’s pulley is turned by a belt which is turned by the engine’s crank pulley supplying the charge needed to keep the battery at the voltage it needs to be.